LM386N-4 Not up to expectations

[deadgirl]

Hello all! I used an LM386N-4 to build a small amp for my guitar. I used the typical application in the datasheet and an 8-Ohm 1 Watt speaker. When I play a note lightly the sound goes through. However, when I strum a chord or pluck loudly, the sound cuts out and wont come back until I stop all ringing notes. What is causing this?

Thannks!

 

[deadgirl]

Thanks for looking at my thread (to the 40 some odd that did), but I just figured it out. Apparently, I needed more than a 1 watt speaker if I wanted to fully utilize +200 gain.

 

[Mooly]

If the sound cuts out completely and doesn't with a different speaker then it's just possible the speaker is faulty. It's not that uncommon for the voice coil to go intermitent open circuit when driven (it's a common fault scenario on old TV's).

The gain (200) shouldn't have anything do with it as long as you are not driving the amp into clipping... and any small speaker should work.

 

[imfree707]

N-4 version

I'm building a project at the moment and was studying the LM386's any way. The N-4 version of LM386 is designed to operate up to about 16 volts BUT not every one mentions that proper load is 32 ohms for the LM386 N-4! The chip's overcurrent protection is probably kicking in.

 

[Michael Bean]

The LM386-4 will drive an 8 ohm speaker just fine if the supply voltage is reduced to around 7 - 9 volts.

Mike

 

[imfree707]

Nice Tip!

The LM386-4 will drive an 8 ohm speaker just fine if the supply voltage is reduced to around 7 - 9 volts.

Mike

Thanks, I was wondering about that! Pretty reasonable that lowering supply voltage would get an N-4 back into safe operating area for an 8 ohm load.